@mixin border-1px($color: red)
{
  position: relative;
  &:after {
    display: block;
    position: absolute;
    left: 0;
    bottom: 0;
    border-top: 1px solid $color;
    width: 100%;
    content: '';
  }
}

@mixin border-none()
{
  &:after {
    display: none;
  }
}

@mixin bg-image($url)
{
  background-image: url($url + "@2x.png");
  @media screen and (min-device-pixel-ratio:3) {
    background-image: url($url + "@3x.png");
  }
}

